'  pijjSTj  ii 


• 


Circular  No.  21,  Revised  Edition. 

United  States  Department  of  Agriculture 

BUREAU   OK   ENTOMOLOGY 

L.  O.    HOWAKD,   EntomolouUt  and  Chief  of 


THE  BTB1WBEBBT  WKKV 

I'.;.     1'.    II.   '   in 

(,i  mi;  m.    vi'i'i  \i:  w«  i      \m>    \  \i  i  1:1:   Ol      \TTAi 


of   the   strawberry   expand    they   are 
them   from   tlic  stem.     This 


Fio.  1.— St  ra  wliTry 
;     .1  nJfcoi 
liffnalii'r.  \<\\;<< 

He.   Qnatlyenl 

"mr's   lllust  r.i- 
Uon). 


Just  before  the  blossoms 
attacked  by  an  insecl  which  severs 
inaecl  is  the  strawberry  weevil,  and  the  severing 
of  the  buds  is  accomplished  by  the  female  in  the 
process  of  oviposition.  The  weevil  lir>t  deposits  an 
m  the  bud  and  then  punctures  or  cuts  the  stem 
below  it  bo  that  in  a  few  days  it  drops  to  the  ground. 
Within  the  severed  bud  the  larva  hatched  from  this 
develops,  and  transforms  to  the  pupa  and 
afterwards  to  the  beetle. 

The  strawberry  weevil  measures  only  a  tenth  of 
an  inch  in  length,  and  is  provided  with  a  slender, 
slightly  curved  snout,  about  half  as  long  as  the 
body,  to  which  are  attached  its  jointed  anteniuc 
The  color  varies  from  nearly  black  to  dull  red.  and 
each  elytron  or  wing-cover  is  ornamented  jusl  be- 
hind the  middle  with  a  dark  spot  surrounded  with  whitish  pubescence 
e  figs  1  and  2). 

The  presence  of  the  weevil  in  strawberry  beds  is  manifested  by  the 
decreased  number  of  blossoms  and  the  severed  buds 
and  steins,  the  diminutive  size  of  the  beetle  protecting 
it  from  general  observation.  Nor  is  the  destruction 
of  the  buds  likely  to  be  noticed  until  some  time  after 
the  insect  has  been  at  work.  Heine  it  happens  that 
injury,  even  over  wide  areas,  is  often  attributed  to 
hail,  frost,  or  to  some  other  cause  than  the  right  one. 
Appearing,  as  the  insecl  bo  often  does,  in 
numbers  almost  from  the  outset,  its  injuries  arc  se- 
vere even  in  seasons  when  only  a  moderate  percent- 
:'  a  crop  is  1"-'.  because  the  blossoms  chiefly  in- 
jured are  the  earliest,  and  eon-eo.uenUy  (ije  short 
is  largely  in  the  early  fruit,  or  that   which  coinrai  0M 

market  price. 

l— Cir.  21 


< 


■ 
il   (AiUhono- 
mu.' 

ifrom  Ilil' 


FOOD    PLANTS    AND    RAVAGES. 

Fortunately  the  weevil  is  restricted  to  the  staminate  varieties  of 
the  strawberry  and  to  such  pistillate  varieties  as  are  imperfect  and 
furnish  a  considerable  quantity  of  pollen,  since  it  is  this  substance 
that  constitutes  the  chief  food  supply  of  both  larvae  and  adults. 
This  explains  the  well-known  preference  of  the  insect  for  such 
varieties  as  the  "Sharpless,"  "Charles  Downing,"  "Jessie,"  and 
'Wilson."  Among  imperfect  pistillates  "Crescents"  are  often 
attacked.  A  frequent  source  of  damage  is  by  the  destruction  of  the 
staminates  used  in  the  fertilization  of  the  pistillates,  the  product 
being  dwarfed  and  unsalable  fruit.  The  susceptibility  of  different 
varieties  appears  to  be  in  direct  proportion  (1)  to  the  quantity  of 
pollen  produced  and  (2)  to  the  amount  of  exposure  of  the  buds  and 
flowers  to  the  sun. 

It  is  fortunate  also  that  this  weevil,  like  so  many  other  trouble- 
some species,  is  more  or  less  intermittent  in  its  attack,  appearing  in 
great  abundance  for  one  or  more  seasons  in  certain  districts  and  doing 
a  vast  amount  of  damage,  and  then  without  any  apparent  reason 
relapsing  into  comparative  obscurity  only  to  reappear  after  a  number 
of  years  and  in  perhaps  some  new  locality. 

This  insect  does  not  confine  itself  to  the  cultivated  strawberry, 
although  this  appears  to  be  its  favorite  food,  but  attacks  in  like 
manner  wild  strawbeny,  blackberry,  dewberry,  and  occasionally 
the  black-cap  raspberry.  The  buds  of  the  common  yellow-flowered 
cinquefoil  (Potentilla  canadensis)  and  of  the  red-bud  tree  (Cercis 
canadensis)  are  similarly  destroyed  by  the  weevil.  All  of  the  above- 
mentioned  plants  serve  as  food  for  the  larva.  The  beetle  frequents 
also  other  flowers  for  feeding  purposes.  It  is  a  lover  of  light  and 
warmth  and  works  most  actively  during  bright,  sunshiny  days. 

DISTRIBUTION    AND    INJURIOUSNESS. 

The  strawberry  weevil  is  a  native  species  and  widely  distributed. 
Its  present  known  distribution  includes  Canada  from  Prince  Edward 
Island  to  Alberta,  the  Atlantic  States,  and  a  portion  of  the  Southern 
States,  and  it  probably  occurs  in  all  of  the  Middle  States.  Its  precise 
limits  southward  and  westward  have  not  been  ascertained.  At 
present  it  occupies  what  are  known  as  the  Upper  Austral  and  Transi- 
tion zones  and  a  portion  of  the  Boreal  zone. 

This  weevil  was  first  noticed  as  injurious  in  1871,  at  Silver  Hill, 
Md.  In  the  next  twenty  years  injuries  were  reported  during  different 
seasons  in  localities  in  Missouri,  Michigan — in  both  the  upper  and 
lower  peninsulas — Staten  Island,  New  York,  the  Provinces  of  Ontario 
and  Quebec  in  Canada,  Pennsylvania,  and  Virginia.  From  that  time 
until  the  present  (1908)  rather  general  injur}-  has  been  noted  in  the 

[Cir.  21]  ' 


berry-growing  portions  of  Virginia,  Maryland,  North  Carolina,  and 
Delaware,  ami  instances  of  attack  hawe  been  reported  from  New 
Hampshire,  southern  Nem  Jersey  ,  Pennsylvania,  New  York,  Connecti- 
cut, Rhode  Island,  Arkansas,  and  Texs 

Ajb  previously  intimated,  many  fruit-growers  are  so  little  familiar 
with  the  strawberry  weevil  thai  ourexacl  knowledge  of  its  injurious- 
ness  i>  limited  to  reports  from  correspondents  who  have  the  worsi 
experience  with  this  pest.  It  is  fairly  positive  that  the  strawberry, 
and  occasionally  the  blackberry  crop,  of  Maryland  and  Virginia  is 
annually  levied  upon  l>\  this  pernicious  little  creature  at  a  rate  of 
from  .")  to  20  per  cent .  a  loss  I  hat  would  seldom  l>e  fell .  or.  if  no!  iced. 
might  not  be  attributed  to  this  weevil.  We  have  creditable  informa- 
tion that  such  lias  Keen  the  condition  in  Virginia  since  about  lsss, 
and  in  Maryland  since  1885.  Dr.  James  Fletcher,  Dominion  ento- 
mologist, states  that  he  ha-  occasional  reports  of  injury  by  this  insect 
everj  year  in  Canada. 

The  greatest  amount  of  loss  from  t  he  St  raw  hen  \  u  ee\  il  w  as  reported 
in  1892,  when  a  shortage  of  two-thirds  of  the  yield  in  portions  of 
Maryland  and  Virginia  was  incurred,  a  considerable  proportion  of 
which  was  without  doubt  referable  to  this  insect.  In  1896  half  of  the 
-t  rawberry  crop  of  Mai  \  land,  according  to  W.  <  i.  Johnson's  estimate, 
was  destroyed. 

In  1898  a  less  serious  outbreak  occurred,  injury  being  mosl  pro- 
nounced in  Delaware  and  Maryland.  In  1902  the  insect  returned  in 
numbers  to  the  same  district.  In  1904  the  injury  to  the  Btrawberry 
by  this  species  in  North  Carolina  was  estimated  at  $100,000,  the  i 
varying  from  10  to  50  per  cent.  Considerable  injury  in  that  State 
has  been  reported  during  1908;  in  Columbus  County  and  vicinity  a 

irtage   of  50   per  cent  was  estimated,  from   which   the   money  l< 
was  placed  at  $700,000. 

NATURAL    HISTORY    AND    HABITS. 

At.  or  a  few  days  before  the  time  of  the  first  blooming  of  the 
earliest  staminate  varieties  of  -t  raw  berry,  this  weevil  emerges  from  its 
winter  quarters  and  Hies  to  the  nearest  flowers  and  Btrawberry  beds. 
Tin-  period  begins  in  the  latitude  of  the  District  of  Columbia  a-  early 
some  seasons  a-  the  middle  of  April,  hut  farther  north  the  in 
doe-  not  appear  until  May.  The  beetles  evidently  continue  to  issue 
from  their  places  ()f  hibernation  for  at  lea-!  a  month,  though  their 
principal  damage  is  done  during  the  first  two  or  three  week-.  After 
feeding  and  making  provision  for  the  continuance  of  their  species  the 

iplaint.-;  are  sometimes  made  of  this  species  in  tin-  Rocky  Mountain  n 
tally  in  Montana,  but  the  culprit  in  <\\ch  cases  is  undoubtedly  a  <lil'lervnt  gp< 
viz,  the  so-called  strawberry  crown  girdler   Otu  hynd  1 

-  -"'] 


Fig.  3. — Strawberry  weevil  (Anthcnomus signatus) : 
a,  b,  Strawberry  spray,  showing  work  in  bud  and 
stem,  natural  size;  c,  outline  of  egg;  d,  larva:  e, 
head  of  larva,  much  enlarged;  /.  pupa;  g,  open 
bud,  showing  egg  on  left  and  punctures  made  by 
snoutof  beetleon  petals.  (Author's  illustration.) 


beetles  die  and  are  replaced  by  a  now  brood  winch  hibernates  in  its 

turn.  « 

Injury,  as  already  stated,  is  due  to  the  work  of  the  female  in  the 

course  of  oviposition.     Selecting   an   unopened,  nearly  mature  bud 

she  perforates  with  her  beak  the 
corolla  or  outer  husk  and  turning 
about  deposits  in  the  hole  thus 
formed  a  single  egg  (shown  in 
outline,  greatly  enlarged,  at  fig- 
ure 3,  c) .  She  then  crawls  to  the 
pedicel  or  flower-stem  just  below 
the  bud  and  with  the  microscopic 
but  scissors- like  mandibles  at  the 
extremity  of  her  beak  deliber- 
ately punctures  or  cuts  it  in  such 
manner  that  the  portion  contain- 
ing the  bud  hangs  by  a  mere 
shred  of  the  epidermis  and  soon 
afterwards  falls  to  the  ground. 

The  object  attained  by  the 
parent  insect  in  puncturing  the 
stem  is  twofold :  ( 1)  The  develop- 
ment of  the  bud  is  arrested,  and 

its  outer  envelopes  of  sepals  and  petals  remain  folded,  thus  retaining 

the  eggs  or  growing  larvae  of  the  insect  and  the 

pollen  on  which  the  latter  feed;  (2)  the  bud  falling 

to  the  ground  is  kept  moist,  whereas  if  permitted 

to  remain  upon  the  stem  it  would  eventually  have 

become  so  dry  as  to  prevent  the  development  of 

the  insect  within.  Ordinarily  a  single  larva  in- 
habits a  bud,  but  in  exceptional  cases  two  indi- 
viduals may  develop  in  one  bud. 

In  from  four  to  six  or  seven  days  after  the  eggs 

are  deposited  the  minute  whitish  or  yellowish  lar- 
vae are  hatched.     These  begin  to  feed  upon  the 

pollen  within  the  buds,  and  when  this  is  devoured 

attack    the   harder  portions.     In    three   or  four 

weeks'  time  they  have  attained  full  growth  and 

present   the   appearance    shown,   enlarged,    at  d 

(fig.    3).     The   larva   now   forms  in   the   bud   a 

hollow  cocoon-like  receptacle  in  which  the  pupa 

(f) ,  and  afterwards  the  adult  condition,  is  assumed. 

The  pupal  stage  lasts  frorn  five  to  eight  days, 

depending,  as  do  all  these   periods,   upon   the   temperature,   where 

upon  the  adult  beetle  develops  and  cuts  its  way  out  of  the  bud. 
The  entire  life  cycle  requires  only  twentv-eight  or  thirty  days. 

rCir.  211 


Fig.  4. — Spray  of  straw- 
berry plant  showing  wee- 
vils at  work.  Natural 
size  (from  Riley). 


Iii  the  vicinity  of  the  District  of  Columbia  the  first  mature  insects 
of  the  new  generation  begin  to  issue  from  the  severed  buds  toward  the 
end  of  Ma\ .  continuing  through  the  month  of  June  and  even  in  some 

es  into  July.     The  beetles  of  this  oevi  generation  Bometimee  con- 
gregate on  tin-  Bowers  of  the  strawberry  in  immense  numbers, 
Bhown   in   figure    t.     The   wild   bergamol    or  horse-mini   (Monarda 
'asa)  is  also  frequented  by  the  beetles  in  like  manner. 

After  feeding  for  a  few  days  the  beetles  disappear  in  quest  of  suit- 
able places  for  passing  the  winter.  Hibernation  evidently  begins 
v«M\  early,  as  the  beetles  are  seldom  seen  after  the  middle  of  July. 

Our  observations  indicate  only  a  single  generation  annually. 

The  adult  beetles  often  perforate  the  buds  for  the  Bole  purpose  of 

f ling,  although  they  feed  also  upon  the  pollen  in  the  flowers,  and 

upon  the  petals. 

Under  ordinary  circumstances  they  do  not  attack  the  foliage,  and 
ip  \  er  the  fruit. 

\  vn  i: ai.   i:\K\iiK.s. 

Four  species  of  hymenopterous  insects  are  parasitic  on  the  Btraw- 
*berry  weevil,  and  to  a  certain  extent  help  to  reduce  its  numbers,  but 

they  are  useful  only  as  they  limit  the  generation  that  hibernates  and 
which  may  <>r  may 


not  survive  in  sufE 
cient  numbers  to  be 
troublesome    in    the 
ensuing    year.     The 

ies  thus  far  hied 
from  severed  buds 
are  Sigalpkus  tibiator 

--..  Bracon  antho- 

nomi  Ashm..  i  'atolac- 

eiM  atdhonomi  Ashm. 

and  ( '.   inn  r- 

Ashm. 

T\\()  snecies  of  l)I"e-     *"'''■    '      '  ■'"'''"  "*  'inthonomi,  a  par.t.-iic  of  the  strawberry  weevil: 
•I  '  Vtlult  frmaleaml  antenna  of  male.     Greatly  enlarged 'origin 

daceous     ants     have 

also  been  observed,  actively  engaged  in  destroying  the  larva'  within 
the  buds,  and  where  ant    bills  are  present  in  strawberry  beds  it  is 

probable  that  few  beetles  will  develop  from  the  buds.      The  species  of 

ants  observed  are  Formica fusca  L.  and  AphxThogaster fulva  R< 

No  insect,  bird,  or  other  animal  has  yet  been  seen  to  prey  upon 

th«'   adult    beetle-.      Fowls,   even  chicks,   are  of  no  >ervice   whatever. 
as  they  roam  through  infested  patches  of  berries  without  offering  to 
molest  the  weevils,  which  are  so  small  and  so  quick  as  apparently  to 
entirely  escape  their  watchful  I  J 
[Or.  a] 


METHODS    OF    CONTROL. 

The  strawberry  weevil  i-  an  extremely  difficult  insect  to  combat. 
The  very  nature  of  the  insect  and  its  life  economy  enable  it  to  evade 
most  measures  that  are  in  successful  use  against  leaf-feeding  species. 
The  fact  that  the  larva'  live  concealed  within  the  buds  places  the 
insect,  in  its  earlier  stages,  beyond  the  reach  of  the  arsenicals.  and 
the  further  fact  that  the  adult  derives  its  chief  sustenance  from  the 
pollen  within  the  buds  and  does  not  feed  upon  the  leaves  limits  the 
effectiveness  of  any  direct  poison. 

PREVENTIVES. 

Covering  the  heds. — Owing  to  the  difficulty  of  contending  with  the 
insect  when  once  it  has  invaded  a  strawberry  bed,  it  is  necessary  to 
have  recourse  to  preventive  measures. 

A  nearly  perfect  preventive  consists  in  covering  the  beds.  This 
covering,  which  may  be  of  muslin  or  some  similar  light  material,  if 
properly  applied  will  not  only  exclude  the  weevil  and  other  noxious 
insects,  but  will  secure  immunity  from  frost  and  is  moreover  a  posi- 
tive benefit  to  the  berries,  which  ripen  a  week  or  ten  days  earlier  and* 
are  superior  also  in  quality  and  size.  Whatever  covering  is  employed 
should  be  put  in  place  over  the  beds  at  least  a  week  before  the  appear- 
ance of  the  first  blossoms  and  may  be  safely  removed  as  soon  as  the 
first  berries  are  ready  for  market.  Pistillate  plants,  or  those  which 
produce  no  pollen,  require  no  such  protection. 

Cultivating  pistillate  varieties. — It  is  obviously  unsafe,  in  dis- 
tricts where  the  weevil  is  known  to  be  abundant,  to  trust  entirely  to 
staminate  varieties  of  berries.  It  is  advisable,  therefore,  to  grow 
chiefly  pistillate  varieties  and  just  as  few  staminates  as  are  necessarv 
for  the  purpose  of  fertilization.  The  insects,  when  they  become 
abundant,  will  mass  themselves  upon  the  staminate  plants,  where 
they  may  be  destroyed  by  spraying  and  similar  measures.  For  the 
complete  success  of  this  method  of  culture  it  is  essential  that  the 
non-fertilizing  plants  should  be  perfect  pistillates  and  bear  no  pollen. 

Cultivating  profuse-blooming  varieties. — According  to  the  general 
opinion  of  strawberry  growers  on  the  eastern  shore  of  Maryland, 
as  expressed  by  Dr.  F.  P.  Herr,  Ridgely,  Md.,  the  most  satisfactory 
method  of  securing  freedom  from  injury  by  the  strawberry  weevil 
is  to  plant  very  profuse-blooming  varieties,  and  many  have  agreed 
that  the  following,  in  the  order  named,  are  the  best  that  have  been 
tested  to  secure  this  end:  Rio,  Superior,  Tennessee  Prolific,  and 
Gandy.° 

Trap  crops. — In  the  same  manner  that  the  rows  of  staminates 
used  for  fertilization  constitute  a  protection  for  the  other  rows,  cer- 

"  A.  L.  Quaintanee.  Report  .Md.  State  Hort.  Soc,  Baltimore.  1902,  p.  100. 
[Cir.  21] 


tain  varieties,  particularly  Buch  as  bloom  early,  may  be  used  to  pro- 
tecl  later-blooming  plains.  One  of  the  besl  for  this  purpose  is  the 
"Charles  Downing,"  as  it  1  »1* >« » 1 1 1—  earl\  and  it-  blossoms  are  exposed 
to  the  -mi.  By  laying  out  beds  with  "Downings"  or  other  early 
Btaminates  <>n  the  sides  thai  experience  has  shown  t"  be  most  sus- 
ceptible i"  attack  e.g.,  in  protected  sunny  Bpots  or  near  wood- 
land in  which  the  beetles  might  have  hibernated  the  insects  will  be 
attracted  From  the  other  portions  <>l'  tli«'  beds  and  can  be  the  more 
readily  tout  rolled  by  spraying  with  the  arsenicals. 

The  red-bud,  which  blooms  several  day-  earlier  than  the  straw- 
berry,  attract-   the  earlie-t    arrivals  and    might    al-o  -el\  e  as  a   trap. 

From  this  tree  the  insects  can  lie  jarred  upon  -hect-  saturated  with 
kerosene,  and  destroyed,  together  with  the  buds  containing  the 
insect's  eggs. 

A-  a  lure  for  the  neu  brood  the  wild  bergamol  i-  of  value.  When 
the  hectic-  gather  upon  thi-  plant  thev  may  he  killed  by  spraying 

the  flowers  or  may  he  captured  and  destroyed  by  thousands,  thus 
lessening  the  chance-  of  infestation  for  the  ensuing  year.  For  their 
capture  large  pan-  of  water  covered  with  a  thin  scum  of  kerosene 
w  ill  he  found  useful. 

Both  red-hud  and  wild   bergamol   are  ornamental  plant-. 

Clean  culture-  It  i-  reasonable  to  presume  that  good  is  always 
accomplished  by  clean  culture,  such  a-  results  from  the  clearing 
away  of  wild  or  volunteer  plants  and  the  "burning  nvcr"  in  early 
Boring  of  underbrush  and  weeds.  But  in  regions  where  wild  straw- 
berry  and  blackberry,  Potentilla,  and  red-bud  grow  in  such  profusion 
a-  in  the  neighborhood  of  Washington,  I).  ('..  it  would  appear  that 
little  benefit  would  accrue  from  such  a  course. 

Unsuccessful  remedies.  A  number  of  remedies  that  have  been  tried 
an1  found  to  he  unsatisfactory.  Capturing  the  hectic-  with  a  sweep- 
net  has  been  suggested,  hut  thi-  species  i-  not  readily  taken  by  this 
method.  Among  the  various  substances  that  have  been  used  in 
experiment-  and  found  unsatisfactory,  either  as  deterrents  or  in- 
secticides, may  he  mentioned:  Lime,  ashes,  dissolved  bone,  ammonia 
in  the  form  of  hen  manure!,  kerosene  and  plaster,  Paris  green  and 
plaster,  a  mixture  of  "tobacco  dust,  lime,  Pari-  green, and  coal  oil." 
pyrethrum,  whale-oil  soap,  and  a  solution  of  sulphate  of  copper  and 
lime.  Even  kerosene  emulsion  ha-  been  only  partially  successful. 
Pyrethrum  has  little  or  no  effect  when  used  in  the  open  field. 


REPELLEN  I  - 


.1  good  repellent  needed. — From  the  nature  of  the  insect's  work  it 
is  obvious  that  whatever  is  used  must  he  of  rapid  action.  What  i- 
nio-t  needed  i-  i  good  repellent.     For  this  purpose  we  would  advise 

[Cir.Ji] 


8 

a  trial  with  a  spray  of  crude  carbolic  acid,  used  in  the  proportion  of 
1  part  to  100  of  water.  This  preparation  has  been  reported  a  suc- 
cessful protection  against  the  rose-chafer  in  vineyards. 

Bordeaux  mixture.0 — One  of  our  correspondents  has  reported  some 
success  with  Bordeaux  mixture,  and  as  this  substance  has  been  found 
effective  against  other  species  of  beetles,  where  Paris  green  failed,  it  is 
well  worthy  of  further  trial.  It  affords  protection  to  plants  by  ren- 
dering the  foliage  distasteful  to  the  insects.  Bordeaux  mixture  has 
the  advantage  of  being  a  fungicide,  for  which  purpose  it  is  mostlv 
used,  and  should  the  plants  be  also  affected  with  blight,  as  is  so  often 
the  case,  it  will  fulfill  a  double  purpose.  In  case  Paris  green  is  used 
the  Bordeaux  mixture  should  be  employed  as  a  diluent  in  the  place 
of  lime  and  water  in  the  preparation  of  this  arsenical. 

ARSENICAL    SPRAYIXG. 

The  arsenicals,  as  already  stated,  can  not  be  depended  on  to  pro- 
duce as  good  results  as  against  leaf-feeding  insects,  for  the  reason 
that  the  adult  weevils  do  not  feed  on  the  foliage,  and  hence  may  be 
reached  only  when  they  feed  on  the  open  blossoms  or  cut  through  the 
corolla  of  the  buds  or  flower-stems  during  opposition.  The  larvae 
can  not  be  affected  at  all  by  any  other  known  insecticide. 

The  arsenicals  do  not  commend  themselves  to  the  average  straw- 
berry grower,  because  of  the  fear  of  poisoning  the  consumer,  but  ex- 
periment has  shown  that  there  is  not  the  slightest  possibility  of  the 
poison  remaining  upon  the  fruit,  since  the  spray,  to  have  any  effect 
on  the  weevil,  must  be  applied  while  the  plants  are  in  bud  or  blossom, 
the  last  application  being  made  two  or  three  weeks  before  the  first 
berries  ripen.  One  of  our  correspondents  has  met  with  sufficient  suc- 
cess with  arsenicals  to  justify  further  tests. 

Paris  green  may  be  used  at  the  rate  of  from  1  to  2  pounds  of 
poison  to  100  gallons  of  water,  and  arsenate  of  lead  at  the  rate  of 
from  1  to  2  pounds  to  25  gallons  of  water.  In  their  preparation  it 
will  be  advisable  to  use  Bordeaux  mixture  as  a  diluent,  particularly 
if  blight  is  present  in  the  beds. 

It  should  also  be  remembered  that  the  arsenicals  act  with  good 
success  on  other  insects  that  may  be  present  on  the  vines;  for  example, 
on  the  strawberry  slugs,  leaf-rollers,  and  the  adults  of  the  root-borers. 

Directions  for  spraying. — To  obtain  the  best  results  it  is  necessary 
to  spray  the  vines  a  day  or  two  before  blooming,  again  two  or  three 
days  after  the  first  bloom,  and  again  five  or  six  days  after  that,  at 

"Directions  for  the  preparation  of  this  fungicide  and  the  arsenicals  here  discussed 
are  given  in  Farmers'  Bulletin  127,  U.  S.  Department  of  Agriculture,  which  can  be 
obtained  gratis  on  application. 

[Cir.  21] 


g 

[eas!  three  applications  being  made  al  intervals,  th<  differenl  applica- 
tions being  graded  with  a  view  to  keeping  the  buds  and  blossoms 
cons  tan  tl)  covered  with  a  thin  coating  of  whatever  Bubstance  is  used. 
Thus,  if  the  variety  of  berry  t..  be  treated  begins  to  bloom  April  _'7, 
it  might  be  sprayed  on  the  24th  or  25th,  again  on  the  29th  or  30th, 

and  a  third  time,  say  Ma\   5.     It   is  doubtful  if  a  f th  spraying 

u,,ultl  be  profitable,  unless  more  frequent  applications  be  made, 
except  in  the  event  of  rain  <>r  heavy  de*  fall  after  spraying,  as  1 1 » *  - 
chief  damage  is  done  usually  during  the  first  two  weeks  of  blooming. 

The  best  form  of  apparatus  for  spraying  garden  plant-  is  a  knap- 
Back  sprayer,  fitted  with  the  finest  Vermorel  Bpray-nozzle,  bul  for 
larger  beds  a  spray  tank  mounted  <>n  a  cart  or  wagon  should  be 
used. 

The  periodica]  or  intermittent  nature  of  this  insect  has  always  mili- 
tated against  its  successful  treatment.  Fruit-growers  are  too  prone 
to  "trust  to  luck"  until  it  Lb  too  late  for  the  application  of  remedies 
with  any  degree  of  promise.  It  should  be  borne  in  mind  thai  what- 
ever course  of  remedial  or  preventive  treatment  i-  pursued  musl  l>e 
begun  I'ifnn  the  insect  appears.  Two  week-'  uninterrupted  work  on 
the  part  of  the  insect  is  sufficient,  during  it-  year-  of  abundance,  so 
to  damage  a  crop  as  to  make  it  unprofitable  for  picking. 

-i  mm  \i:i  . 

It  may  be  well  to  summarize  briefly  what  ha-  previously  been 
said  under  the  heading  of  "Methods  of  Control."  No  single  remedy 
will  entirely  eradicate  this  in-eet  from  an  infested  locality,  and  after 
B  -trawherrv  bed  i-  mice  badly  infested  the  crop  can  not  he  saved 
that  year  unless  remedial  measures  are  at  once  instituted.  Prevent- 
ives are  preferable  to  direct  remedies.     These  are.  in  brief,  as  follow-: 

(1)  Covering  the  beds  with  muslin  or  similar  material.        See  p.  6.) 

(2)  Cultural  remedies,  including  the  cultivation  of  pistillate  and 
profuse-blooming  varieties  of  the  strawberry,  the  use  of  trap  crop-, 
and  clean  culture.  All  of  these  should  he  put  into  operation  wherever 
possible.      (See  pp.  (i  and  7.) 

(3)  The    repellents    advised,    and    especially    Bordeaux    mixture 

mould  he  given  a  thorough  test. 

(4)  In  addition  to  Paris  green,  and  Pari-  green  combined  with 
Bordeaux  mixture,  arsenate  of  lead  should  he  thoroughly  tested,  as 
it  may  in  the  end  prove  to  he  the  best  direct  remedy. 

Finally,  a  good  word  should  he  added  for  the  cultivation  of  pistil- 
late varieties.  These  have  been  thoroughly  tested,  a-  advised  on  page 
6,  in  Maryland  and  Virginia  in  the  vicinity  of  the  District  of  Colum- 
bia for  many  year-,  with  the  result  that   practically  no  complaints 

[Cir.  21} 


10 

of  serious  injury  from  the  strawberry  weevil  are  now  made.  This 
is  the  result  of  advice  given  to  all  growers  in  this  section  who  could 
be  reached,  they  in  turn  passing  on  the  information  to  their  neighbors. 
Cooperation  is  absolutely  essential  in  the  treatment  of  most  injurious 
pests,  and  the  strawherry  weevil  is  a  striking  example  of  this. 

Approved: 

James  Wilson, 

Secretary  of  Agriculture. 

Washington,  D.  C,  June  26,  1908. 

[Cir.  21] 

o 


UNIVERSITY  OF  FLORIDA 


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